This invention relates generally to tracking systems and more particularly to adaptive gated centroid tracking systems.
Each of the various prior art video tracking systems, although performing satisfactorily for some applications, have limitations when applied to the total range of applicable uses. For example, prior centroid trackers, while possessing excellent performance characteristics in the presence of noise and in the acquisition of the targets, have restricted usefulness in applications where the target image size exceeds that of the fixed size video tracking gates. Attempts to incorporate adaptive gating into these centroid trackers have encountered serious difficulties, such as an unacceptable increase in complexity, inherent with the computation technique and mechanization of the prior systems. On the other hand, "gradient" and "area balance" type systems incorporating "blooming" target image tracking features have reduced performance capabilities in the presence of noise and/or in the acquisition of targets. An important aspect of the subject invention is the recognition of the complementary limitations of these two types of prior art systems and the development of a mechanization which is practical to implement, reliable in operation and which provides the advantages of both prior art techniques.